While I love monsters, I'm going to go with robots. We're talking about fictional robots and monster I assume so yeah, Robots. They can analyse the monster and it's anatomy, Find a weak spot and boom. Monsters only rely on instinct, Which is helpful in some cases but definitely not robots. Also robots have no emotions, So intimidation from them is impossible. I wish I could comment on the comment on the left side because there are definitely flaws in "YourBoyTom"s argument.

Monsters can evolve biologically, While robots have technology on their side. However, Someone has to maintain those robots and without proper care, Those rust buckets are done for. Monsters are naturally ferocious and cunning.